Result: standard mapping
How many E0s are in an ODU4?
An ODU4 carries 1,209,600 E0s, per ITU-T G.709, ITU-T G.707 and ITU-T G.704. This path maps STM-64 into ODU2 as a client, then follows that client's tributaries.
1,209,600
E0s in an ODU4
Working
ODU4 → 10 × ODU2 → 1 × STM-64 → 64 × STM-1 → 63 × E1 → 30 × E0
- 10 × ODU2 in each ODU4 ITU-T G.709Ten ODU2s use all 80 tributary slots, eight slots each.
- 1 × STM-64 in each ODU2 ITU-T G.709Client mappingCBR STM-64 mapped into OPU2.
- 64 × STM-1 in each STM-64 ITU-T G.70764 × STM-1.
- 63 × E1 in each STM-1 ITU-T G.70763 VC-12 tributaries: 3 TUG-3 × 7 TUG-2 × 3 TU-12.
- 30 × E0 in each E1 ITU-T G.70430 voice channels in 32 timeslots. TS0 is framing and TS16 is channel-associated signalling.
- 10 ODU2s
- 10 × 1 = 10 STM-64s
- 10 × 1 × 64 = 640 STM-1s
- 10 × 1 × 64 × 63 = 40,320 E1s
- 10 × 1 × 64 × 63 × 30 = 1,209,600 E0s
Leftover capacity
27.380045815 Gbit/s of each ODU4 line rate (104.794445815 Gbit/s) sits outside 1,209,600 × 64 kbit/s of E0 line rate (77.414400 Gbit/s). That remainder is overhead, fixed stuff or justification. It is not another whole tributary.
By bit rate only
Dividing the line rates gives 1,637,413.21, which floors to 1,637,413 E0s by bit rate only. The standard mapping is 1,209,600. Use the mapping.